Answer: Based on your description I am not certain what the problem is -- or if there is a problem. Some varieties of tulip, especially among the early cottage and species types, have leaves that are mottled and reddish, so what you are seeing could be normal. Sun damage would normally look like the leaves are drying out rather than turning red. There is also a situation (crown rot) where leaves could turn red and then wilt, in which case the infection is also underground and the entire bulb and soil should be disposed of in the trash to prevent it infecting other plants. (The pot should also be sterilized.) But this last is very unusal in tulips and it would surprise me if that is it.
Q&A Library Searching Tips